Micofabricated Cantilever-Based Scanner for forward-looking 3D Endoscopic Optical

描述(申请人提供)：该项目旨在开发一种新型的二维光学扫描仪，以实现内窥镜前瞻性三维光学相干层析成像。内窥镜OCT(EOCT)通过在各种组织中原位进行断层亚表面成像的“光学活组织检查”为微创诊断提供了可能性。基于导管的EOCT是通过放置在内窥镜内的导管传递光束来执行的。导管OCT探头已经开发出使用侧视几何结构，这适合于成像狭窄的管腔血管。前瞻探头可以大大提高胃、结肠、膀胱等大器官或中空器官的黏膜成像能力，但由于导管大小的限制，实施起来比较复杂。已经报道了实现前瞻性EOCT的方法，并且由于在小导管直径(2.9 mm)内插入二维光学扫描仪的困难，通常提供一维扫描。给出一个导管集成的二维光学扫描仪，使用位于内窥镜外部的参照束进行纵向扫描可以获得高分辨率的3DEOCT成像。这种成像方法将允许对癌症和其他穿透深度有限的上皮层或近上皮下层的癌症和其他病理进行准确的非侵入性诊断。 本文提出的新型二维光学扫描仪的设计是基于微结构悬臂梁的。静态偏转和共振频率的计算表明，在合理的参数设置下，所提出的方案在尺寸和功耗方面优于竞争方案，并且具有良好的扫描范围和速度性能。本项目致力于为导管OCT成像优化的二维扫描仪的微制造和表征。微加工工艺步骤将被设计为包括基于计算的致动器几何形状和薄膜厚度对扫描性能的影响而选择的一系列参数。这些设备的机械和光学特性将用一套可用的测量工具来表征。将根据光学扫描仪的实际性能对EOCT系统进行详细的光学模拟。优化的设备将与合适的光学组件集成在一起，并集成到高速傅立叶域OCT扫描仪中，以评估图像质量。

DESCRIPTION (provided by applicant): This project aims at the development of a novel two-dimensional optical scanner to enable endoscopic forward-looking 3D Optical Coherence Tomography. Endoscopic OCT (EOCT) provides the potential for minimally invasive diagnostics by "optical biopsy" consisting of tomographic sub-surface imaging in situ in a variety of tissues. Catheter-based EOCT is performed by delivering the light beam through a catheter placed inside an endoscope. Catheter OCT probes have been developed using a side-looking geometry, which is appropriate for imaging narrow-lumen vessels. A forward-looking probe would greatly enhance the ability of imaging mucosa of large or hollow organs such as stomach, colon, and bladder, but the implementation is complicated by the catheter size constraints. Approaches to achieve forwardlooking EOCT have been reported and typically offer uni-dimensional scanning due to the difficulty of inserting a two-dimensional optical scanner within the small catheter diameter (2.9 mm). Given a catheter-integrated, two-dimensional optical scanner, high resolution 3D EOCT imaging can be obtained using longitudinal dimension scanning with the reference beam located outside the endoscope. This imaging approach will allow accurate non-invasive diagnoses of cancers and other pathologies limited in depth of penetration to epithelial or near sub-epithelial layers. The novel design for the two-dimensional optical scanner proposed here is based on microfabricated cantilevers. Static deflection and resonance frequency calculations indicate that, for a reasonable set of parameters, the proposed scheme provides a size and power consumption advantage over the competing approaches and excellent scanning range and speed performance. This project is focused on the microfabrication and characterization of a two-dimensional scanner optimized for catheter OCT imaging. The microfabrication processing steps will be designed to include a range of parameters selected based on the calculated effects of actuator geometry and film thicknesses on scanning performance. The mechanical and optical properties of the devices will be characterized with a suite of available measurement tools. A detailed optical simulation of the EOCT system will be performed based on actual performance of the optical scanner. Optimized devices will be integrated with suitable optical components and incorporated into a high-speed Fourier-Domain OCT scanner to assess image quality.